(a) Technical Field
The present invention relates to a high-durability metal foam-supported catalyst which exhibits superior thermal conductivity and high temperature stability in order to inhibit degradation of catalytic performance in steam carbon dioxide reforming due to non-uniform temperature and a method for preparing same.
(b) Background Art
The catalysts mainly used in the field of reforming are a powder-type catalyst and a pellet-type support catalyst. Although the powder-type catalyst is superior in many aspects because of superior dispersibility, it is difficult to be used directly for industrial purposes. The powder-type catalyst is discharged from a reformer together with a reaction product. Accordingly, the powder-type catalyst may be accumulated near the outlet and block the flow tube. This makes the powder-type catalyst inapplicable to an industrial-scale reformer.
The pellet-type support catalyst is frequently used for industrial reformers. Although the performance of the pellet-type support catalyst is not better than that of the powder-type catalyst, it does not block the flow tube. Accordingly, it can be used for a longer period of time than the powder-type catalyst. But, the pellet-type support catalyst is disadvantageous in that the frequently used γ-Al2O3 pellet is brittle because of weak structural strength. Further, since the pellet-type support catalyst has a larger volume than the powder-type catalyst, the volume increases significantly when it is used for a large-capacity reformer.
All reforming reactions are sensitive to reaction temperature. But, when the existing powder-type catalyst or pellet-type catalyst is used, heat is not uniformly distributed throughout the reactor because of poor thermal conductivity.
Existing technologies for a catalyst support or a catalyst for hydrocarbon reforming are as follows. Korean Patent Application No. 10-2001-7005646 discloses a steam reforming catalyst which is supported on a mesh or a mesh-type material or the catalyst itself is of a mesh type. The mesh-type material may be wire, fiber mesh, metal felt, gauze, metal fiber filter, etc. Whereas this catalyst is limited for use in steam reforming, the present invention provides a catalyst for steam carbon dioxide reforming as described below. Also, whereas the catalyst itself is coated on a support in the above-described technique, an additional layer is coated on a metal foam support through wash coating and then a catalyst is disposed thereon in the present invention. As a result, a remarkable effect unexpectable from the existing catalyst is achieved.
Korean Paten Application No. 10-2004-7018719 discloses a reforming catalyst containing bismuth and phosphorus, wherein effective amounts of bismuth and phosphorus are uniformly distributed on a γ-alumina support and catalytically effective amounts of platinum, chlorine and, optionally, rhenium are deposited. Whereas this γ-alumina catalyst is for naphtha reforming, the present invention is different therefrom in that it provides a catalyst for steam carbon dioxide reforming, uses a metal foam, not γ-alumina, as a catalyst support and a nickel-based catalyst is used for steam carbon dioxide reforming.
Korean Paten Application No. 10-2007-7012528 discloses a support material containing silica, alumina, silica-alumina, titanic, titanosilicate, zirconia, zirconosilicate, etc. of various regular or irregular different shapes, including sphere, plate, cylinder, disc, ring, star and others. This invention relates to a catalyst support and a catalyst for production of alkenyl alkanoate, whereas the present invention relates to a catalyst support and a catalyst for production of hydrogen and carbon monoxide for Fischer-Tropsch (FT) synthesis. Whereas the catalyst of the patent application uses a noble metal catalyst such as palladium and gold, the present invention is different therefrom in that it uses a non-noble metal nickel for steam carbon dioxide reforming.
Throughout the specification, a number of publications and patent documents are referred to and cited. The disclosure of the cited publications and patent documents is incorporated herein by reference in its entirety to more clearly describe the state of the related art and the present invention.